Is there any accuracy lost when firing the shorter cased calibers out of revolvers that have a parent cartride that was lengthened to a new magnum type cartridge? I'm talking about the 38s fired in 357 mags, 44 special in 44 mag guns, and 45 colt in 454 Cassul revolvers. Would an average shooter notice accuracy differences in the same pistol firing the 2 cartridges?

Believe there can be, and in most cases is, an accuracy loss...but it's slight. Not from the extra distance to the rifling, but from the bullet having to pass through the forwards section of full diameter chamber before bing caught by the chamber throat. Not much...if you seat a .44specail in a .44mag. chamber, there is a .125" section of .44mag. chamber head of it that measures .456" (or there abouts). IF the base of the bullet expands at exit from the case mouth, that .430" bullet becomes .456" and then is swaged back down to cylinder mouth size. IF the bullet is hard and the pressure low, the base won't expand...may still get a little off center in the larger chamber.

Some tests in old Handloader issues showed a little accuacy loss and a little velocity loss...but not a great deal, tiw as less than the typical gun-to-gun or load-to-load variation typical in all handguns.

The only way to really test it would be to start with the short chamber and then rechamber to the longer case...that's the only way to hold the gun-to-gun variables in check (otherwise, how would you know if you just happened to pick an outstanding .38specail chamber to test it in...or an outstandingly bad one?)

Is there any accuracy lost when firing the shorter cased calibers out of revolvers that have a parent cartride that was lengthened to a new magnum type cartridge? I'm talking about the 38s fired in 357 mags, 44 special in 44 mag guns, and 45 colt in 454 Cassul revolvers. Would an average shooter notice accuracy differences in the same pistol firing the 2 cartridges?

Buddy, I shoot 38's in both my Taurus .357's all the time, and They seem just as accurate as any .357 load I've ever fired and sometimes more because they recoil less and are easier to control. You probably ain't gonna notice. The guys that shoot and Win cowboy action competitions, mostly win with .357 sixguns, with .38 specials in the cylinders.

Walter30-06:cool:

I have a Ruger Blackhawk in 357 Mag with the extra 9mm cylinder and with the 357 mag loads it's very accurate but when i slip in the 9mm cylinder it shoots like a shotgun. I contribute this to the bullet jump and don't shot the 9mm very often. I haven't tried any 38 special in it yet but I probably will someday.

Back when I shot ppc a lot of the guys & gals shot the 6" S&W 357's loaded with light 38's. Some of these folks were very very good. I do not know if there is an accuracy loss or not when switching to a 38. I am sure though that just any 38 will probably not do without some load development and testing. The individual differences from revlover to revolver is probably greater than an inherent accuracy loss.. if there is one.

My official guess for the day! :cool:


Bill

I have a Ruger Blackhawk in 357 Mag with the extra 9mm cylinder and with the 357 mag loads it's very accurate but when i slip in the 9mm cylinder it shoots like a shotgun. I contribute this to the bullet jump and don't shot the 9mm very often. I haven't tried any 38 special in it yet but I probably will someday.

I think it also might have to do that a .357 measures...well .357 and a 9mm measures .355, just like shooting a .22LR out of a barrel made for .22 mags (ie, single six with a convertible cylinder. the long rifle is .220 the magnum is .224.)

Don't think it's so much the long jump to rifling, but more the jump through the space that is chamber sized rather than bullet size. Would probably take a machine rest and hundreds of rounds of ammo to proove it.

Have read tests in Handloader where there has been some indications of velocity loss with jacketed .38spec. loads fired in .357 cylinders. The conclusion was that the 1/10th inch section of chamber diameter gap does tend to let a bit of gas bleed past a hard jacketed (too hard to "bump up"), but that any accuracy loss would be minor.

The 9mm cylinders often are accuracy problems...some shoot quite well, other's are problem children. But the same is true of all 9mm chambered handguns; they're particular about what they will shoot well and won't...357's are a bit easier to please.
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Still have two 9mm revolvers (S&W 940 and a Ruger 101). Had a Ruger S.S. that I 'graphed against a Browning HP using the same handloaded ammo (90gr. loads). The difference was less than 30fps. between the semi-auto and the revolver.

Remember that revolver barrels are measured differently...only the rifled tube is measured. Semi-autos measure from firing pin to crown.

Now the odd thing: using expasnion media (wet paper) the revolver's bullets consistantly penetrated less, expanded more (actually fragmented at the speeds we drove the little 90gr. bullets). Given the near identical velocity, some other factor had to be at work.

Wondered just how fast the 9mm bullet was going after it exited that cylinder..guessing the bullet slamed into the rifling going at a good clip...in combination with the more aggressive rifling of the revolver barrel, probably stressed the jacket material a good bit...and it fractured/fragmented on imact more easily that the bullet from the semi-auto (with less agressive rifling and bullet engagement starting while bullet speed is low).

Curious...but not enough to de-barrel the Ruger SS...used a Dan Wesson. Remove barrel completely and clocked the bullets as they exited the cylinders. Some loads are faster than others, but call 630fps the average. That's not real fast, but it's as fast as some target .38load's muzzle velocity.

So...how much stress would be put on a bullet is if I were to stand back with 630fps "target' loads and managed to actually shoot one into a rifled tube?